[FFmpeg-devel] FFmpeg 3.5 / 4.0

[James Almer]

On 4/19/2018 11:33 AM, Nicolas George wrote:
> James Almer (2018-04-19):
>> Had it been in 3.4 it would have mean a considerable ABI breakage as
>> well, at least without the eventual backwards compat change.
> 
> Can you explain why you think that?
> 
> When advising on these changes and reviewing patches, I was very careful
> that they do not introduce API nor ABI changes.
> 
> Apart from bugs in protocols that were not fixed immediately, the only
> change visible for applications is if they register a custom callback
> for a packet protocol and yet decide to return 0 to indicate EOF.

It would have not been backwards compatible in such scenario to load at
runtime an hypotetical 3.4.x lavf library with that change in an
application that was built against 3.3.x or older. Regardless of 0 being
defined as EOF or not in documentation, the behavior of one library
would have not been the same as the other, at least as i said above,
without the compat change you eventually committed.

It being introduced after a major bump guarantees that any such custom
callbacks will have to be adapted before they work again, so at least
that's good.

> This
> was never a documented practice, is logically absurd (0 is a valid
> packet size) and inconsistent with similar practices (UDP socket do not
> return 0 for EOF).
> 
> Regards,
> 
> 
> 
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